U.S. patent number 5,298,994 [Application Number 07/696,247] was granted by the patent office on 1994-03-29 for television signal converter for converting high definition television (hdtv) signals to conventional television signals.
This patent grant is currently assigned to Kabushiki Kaisha Toshiba. Invention is credited to Takato Katagiri, Kohei Watanabe.
United States Patent |
5,298,994 |
Watanabe , et al. |
March 29, 1994 |
Television signal converter for converting high definition
television (HDTV) signals to conventional television signals
Abstract
A converter for television signals formed of a television signal
converter, a selection position changer and a position display. The
television signal converter converts a first television signal
corresponding to a selected portion of a picture of a first
television system to a second television signal of a second
television system so that the selected portion of the picture of
the first television system fills the entire screen of the second
television system. The aspect ratios of the first and second
television system are different. The selection position changer
changes the position of the selected portion of the picture of the
first television system. The position display displays information
about the position of the selected portion of the picture of the
first television system.
Inventors: |
Watanabe; Kohei (Tokyo,
JP), Katagiri; Takato (Saitama, JP) |
Assignee: |
Kabushiki Kaisha Toshiba
(Kanagawa, JP)
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Family
ID: |
26455561 |
Appl.
No.: |
07/696,247 |
Filed: |
May 6, 1991 |
Foreign Application Priority Data
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May 9, 1990 [JP] |
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2-117452 |
May 9, 1990 [JP] |
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2-117453 |
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Current U.S.
Class: |
348/445; 348/704;
348/578; 348/E7.016; 348/E5.111 |
Current CPC
Class: |
H04N
7/0122 (20130101); H04N 7/0125 (20130101) |
Current International
Class: |
H04N
7/01 (20060101); H04N 5/44 (20060101); H04N
007/01 (); H04N 005/46 () |
Field of
Search: |
;358/11,12,180,183,22,140,141 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1-212970 |
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Aug 1989 |
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JP |
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303286 |
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Dec 1990 |
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JP |
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305190 |
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Dec 1990 |
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JP |
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226192 |
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Jul 1991 |
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JP |
|
Primary Examiner: Groody; James J.
Assistant Examiner: Burgess; Glenton B.
Attorney, Agent or Firm: Banner, Birch, McKie &
Beckett
Claims
What is claimed is:
1. A converter for television signals, said converter
comprising:
television signal conversion means for converting a first
television signal corresponding to a selected portion of a
television picture of a first television system to a second
television signal of a second television system, wherein said
selected portion of said television picture becomes a full picture
on said second television system having an aspect ratio which is
different from the aspect ratio of said first television
system;
selection position change means for changing the position of said
selected portion of the picture of the first television system;
and
position display means for displaying textual information about the
position of the selected portion of the picture of the first
television system on said second television system.
2. A converter for television signals as claimed in claim 1,
wherein the position display means displays information about the
position of the selected portion of the picture of the first
television system in response to a request for displaying the
position of the selected part of the picture.
3. A converter for television signals as claimed in claim 2,
wherein the request for displaying the position of the selected
portion of the picture is output automatically in response to an
operation of changing the position of the selected portion of the
picture of the first television system in the selection position
change means.
4. A converter for television signals as claimed in claim 1,
wherein the position display means displays whether the position of
the selected portion of the picture is predetermined position or
not.
5. A converter for television signals as claimed in claim 1,
further comprising a second television signal conversion means for
converting a third television signal corresponding to a full said
first television system to a fourth television signal corresponding
to a portion of the picture of said second television system where
said full picture of said first television system becomes a portion
of said picture of said second television system.
6. A converter for television signals as claimed in claim 5,
wherein the position display means displays information about the
position of the selected portion of the picture of the first
television system on a display picture under an output of the
second television system conversion means.
7. A converter for television signals as claimed in claim 6,
wherein the position display means displays the position of the
selected portion of the picture of the first television system by a
frame on the display picture.
8. A converter for television signals as claimed in claim 6,
further comprising a picture display change means for changing
picture display from a display picture under an output of the first
television signal conversion means to that of the second television
signal conversion means in response to the change of the selected
portion of the picture of the first television system.
9. A converter for television signals as claimed in claim 6,
further comprising a picture display change means for changing
picture display from a display picture under an output of the first
television signal conversion means to that of the second television
signal conversion means in response to a request for displaying the
position of the selected portion of the picture of the first
television system.
10. A converter for television signals as claimed in claim 5,
wherein the first television system has greater aspect ratio than
that of the second television system.
11. A converter for television signals as claimed in claim 1,
wherein the first television system has greater aspect ratio than
that of the second television system.
12. A converter for television signal as claimed in claim 11,
wherein the first and second television system have the aspect
rations of 16:9 and 4:3, respectively.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of television signal
conversion and, in particular, is directed to a converter which
converts a first television signal in a first television system to
a second television signal for use in a second television system,
wherein the second television signal has a different aspect ratio
than the first television signal.
2. Description of the Related Art
Various high definition television (HDTV) systems having different
aspect ratios than the aspect ratios in conventional television
systems are presently being proposed. One such system is known as
the Hi-Vision system and has an aspect ratio of 16:9 compared to
the 4:3 aspect ratio in a conventional system. A signal converter
is thus required in order to watch a Hi-Vision program on a
conventional television.
Such converters normally provide wide and zoom modes of display
when a Hi-Vision program is displayed on a conventional
receiver.
In the zoom mode, a portion of the picture area of the Hi-Vision
picture fills the entire receiver screen.
FIG. 1 illustrates a Hi-Vision picture 22 displayed on a Hi-Vision
system television screen. Picture 22 having an aspect ratio of
16:19 (A:B=16:9) is formed of zoom portion 20 and side portions 101
and 102. When Hi-Vision picture 22 is displayed on a conventional
television receiver in the zoom mode, portion 20 is converted to
fill the entire picture screen. In the wide mode of operation, the
full Hi-Vision picture, i.e., portion 20 and side portions 101 and
102 are converted to fill a conventional receiver screen. The wide
mode will be described in more detail with reference to FIG. 2.
FIG. 2 illustrates a picture 32 displayed on a conventional
television receiver. Picture 32 is formed of portion 30 and upper
and lower portions 201 and 202. Portion 30 corresponds to a full
Hi-Vision picture. In the wide mode, all portions of the Hi-Vision
picture 22 having an aspect ratio of 16:9 are displayed, for
example, in the center area of the screen with an aspect ratio of
4:3.
In the zoom mode, the screen position of a portion 20 taken from
Hi-Vision picture 22 can be freely selected. That is, as shown in
FIG. 3, the position of selected portion 34 of a Hi-Vision picture
36 is located to the right of the screen rather than the center.
When portion 34 is displayed on a conventional television receiver,
there is no indication provided to the user with respect to the
selected position from which portion 34 was taken from the
Hi-Vision picture. Such an indication would, of course, be useful
to the user as it would enable the user to have more effective
control over the conversion and display process for the Hi-Vision
picture. Accordingly, prior art converters are deficient in this
regard.
SUMMARY OF THE INVENTION
Accordingly, it is an overall object of the present invention to
provide an improved converter for television picture signals which
provides information about the relative screen position of a
selected portion of the television picture.
It is a specific object of the present invention to provide such a
converter which is easy to implement and reliable in operation.
It is another specific object of the present invention to provide
such a converter which is low in cost and can be readily operated
by a user.
In accordance with the present invention, the foregoing objects are
achieved by providing a converter for television picture signals
which comprises a conversion device for converting a first
television signal corresponding to a selected portion of a
television picture of a first television system to a second
television signal of a second television system so that the
selected portion of the picture of the first television system
fills the entire screen of the second television system which has
an aspect ratio which is different from the aspect ratio of the
first television system. A selection position change device is
provided for changing the position of the selected portion of the
picture of the first television system. A position display device
also is provided for displaying information about the position of
the selected portion of the picture of the first television
system.
Other objects, features, and advantages of the present invention
will become apparent from the following detailed description. It
should be understood, however, that the detailed description and
specific examples, while indicating preferred embodiments of the
invention, are given by way of illustration only, since various
changes and modifications within the spirit and scope of the
invention will become apparent to those skilled in the art from
this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the present invention and many of
its attendant advantages will be readily obtained by reference to
the following detailed description considered in connection with
the accompanying drawings, in which:
FIG. 1 illustrates a picture in a Hi-Vision system.
FIG. 2 illustrates a picture in a conventional television
system.
FIG. 3 illustrates another picture in a Hi-Vision system.
FIG. 4 is a block diagram of a converter for television signals
according to the present invention.
FIGS. 5 through 7 illustrate pictures of a conventional television
system provided by the converter shown in FIG. 4.
FIG. 8 is a block diagram of another embodiment of a converter for
television signals according to the present invention.
FIG. 9 illustrates pictures in a conventional television system
according to the converter shown in FIG. 8.
FIG. 10 illustrates a picture of a Hi-Vision system showing the
selection portion illustrated in FIG. 9.
FIG. 11 illustrates a picture in a conventional TV system according
to a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of the present invention will now be
described in more detail with reference to the accompanying
drawings. FIG. 4 is a block diagram of a converter for television
signals according to the present invention.
An input terminal 40 receives a Hi-Vision television signal S1. The
bandwidth of Hi-Vision signal S1 is compressed using a subsampling
transmission scheme such as the multiple Sub-Nyquist-Sampling
Encoding system (MUSE). An intrafield interpolation circuit 42 is
connected to input terminal 40 and receives signal S1. Intrafield
interpolation circuit 42 interpolates each field of the television
signal using a sampling process to produce an original Hi-Vision
signal S2.
A scanning line transformer 44 is connected to intrafield
interpolation circuit 42. Scanning line transformer 44 transforms
Hi-Vision signal S2 having 1125 lines from intrafield interpolation
circuit 42 to a conventional TV signal S3 having 525 lines. A right
and left panel substraction circuit 46 is connected to scanning
line transformer 44. Right and left panel substraction circuit 46
reduces the signal in a manner which corresponds to right and left
panels 101 and 102 (see FIG. 1) from output signal S3 of scanning
line transformer 44. Substraction circuit 46 passes the portion of
the signal which corresponds to portion 20 having an aspect ratio
of 4:3 (see FIG. 1). This signal reduction operation is implemented
by using a switch circuit (not shown) controlled by timing signals
as described below. A time axis transformer 48 is connected to
right and left panels substraction circuit 46. Time axis
transformer 48 transforms the time axis of output signal S4 from
right and left panel substraction circuit 46 in order to produce a
conventional television (TV) signal S5.
A scanning line transformer 50 is also connected to intrafield
interpolation circuit 42. Scanning line transformer 50 transforms
Hi-Vision signal S2 having 1125 lines from intrafield interpolation
circuit 42 to signal S6 having a number of lines (for example, 375
lines) which correspond to portion 30 of the conventional
television picture 32 as shown in FIG. 2.
An upper and lower panel adder circuit 52 is connected to scanning
line transformer 50. Upper and lower panel adder circuit 52 adds
signals which correspond to portions 201 and 202 (FIG. 2) of
conventional TV picture 32. The signals added by upper and lower
panel adder circuit 52 include synchronizing signals and constant
level signals for the picture portion.
A switch 54 is connected to time axis transformer 48 and upper and
lower panel adder circuit 52. Specifically, input terminals 541 and
542 of switch 54 are connected to time axis transformer 48 and
upper and lower panel adder circuit 52, respectively. Switch 54 is
switched by a control signal S7 from a controller 56 as described
below.
An adder 58 is connected to an output terminal 543 of switch 54.
Adder 58 also provides output terminal 60.
Mode change switch 62 and selection position change switch 64 are
connected to controller 56. Switches 62 and 64 are provided for
switching between a wide and zoom mode as the signal transformation
mode and for moving the position of a picture portion taken out of
the Hi-Vision picture (selection position), respectively.
A display controller 66 is also connected to controller 56. Display
controller 66 comprises a character generator which functions to
display within the picture whether the transformation mode is wide
or zoom. Display controller 66 also functions to display within the
picture whether the selection position is the center portion of the
picture (standard position) in the zoom mode. These functions are
controlled by controller 56 according to the transformation mode
designated by switch 62 and the selection position designated by
switch 64.
An output terminal of display controller 66 is connected to the
other input terminal of adder 58. Adder 58 adds output S8 from
display controller 66 to output S9 from switch 54.
Controller 56 controls right and left panel substraction circuit
46, switch 54 and display controller 66. More specifically,
substracting the right and left panels in right and left panel
substraction circuit 46 is implemented by an output S10 from switch
64 through controller 56. Switch 54 is connected to terminals 541
and 542 by controller 56 in the zoom and wide modes,
respectively.
The operation of the embodiment of the present invention shown in
FIG. 4 will now be described.
Each field in band-compressed Hi-Vision signal S1 input from input
terminal 40 is interpolated to produce Hi-Vision signal S2.
Hi-Vision signal S2 having 1,125 lines is transformed to a
corresponding signal having only 525 lines as in a conventional TV
signal by removing lines using scanning line transformer 44. The TV
signals which correspond to the right and left panels of the
picture under signal S3 is then substracted by right and left panel
substracting circuit 46. Substraction is implemented by output
signal S10 from switch 64 through controller 56.
The time axis of output signal S4 from right and left panel
substraction circuit 46 is transformed by time axis transformer 48
to form a conventional TV signal S5.
Output signal S2 from intrafield interpolation circuit 42 is also
transformed to signal S6 with the number of lines corresponding to
portion 30 (FIG. 2) of conventional TV picture 32 by scanning line
transformer 50. Signals which correspond to portions 201, 202 (FIG.
2) of picture 32 are added to signal S6 by upper and lower panel
adder circuit 52 to form signal S11.
If the user selects the zoom mode using switch 62, switch 54 is
connected to terminal 541 by controller 56. Thus, signal S5 is
selected by switch 54 and is output to adder 60. From display
controller 66, a signal corresponding to the characters `ZOOM` 501
(FIG. 5) is output from output S12 of switch 62 through controller
56 and is added to output signal S9 from switch 54 by adder 58. The
picture produced by output signal S13 from adder 58 is, for
example, shown in FIG. 5. Additionally, if the user sets the
selection position to the center position by switch 64, signals
corresponding with a mark area 502 is also output from display
controller 66. Otherwise, mark area 502 is not displayed on the
picture (signal corresponding with a mark area 502 is not output
from display controller 66).
Additionally, and as shown in FIG. 6, characters 601 such as
`CENTER`, `LEFT` or `RIGHT`, may be displayed in mark area 502
according to the output from switch 64. Picture information in the
area 502 may be removed in order to avoid confusion. Moreover,
information about the selection position is not limited to the mark
area scheme discussed above.
If the user selects the wide mode by switch 62, switch 54 is
connected to terminal 542 through controller 56. Thus, signal S11
from upper and lower panel adder circuit 52 is selected by switch
54 and is output to adder 58. Signals corresponding to the
characters `WIDE` 701 (FIG. 7) are output from display controller
66 by the output of switch 62 through controller 56 and are added
to signal S9 from switch 54. A picture produced by output signal
S13 from adder 58 is, for example, shown in FIG. 7.
In the above embodiment, zoom and wide modes are described.
However, the converter for television signals in accordance with
the present invention may have only the zoom mode. As also
described in the above embodiment, a television signal is
transformed from the Hi-Vision to a conventional TV signal.
However, inverse transformation also may be applied.
FIG. 8 is a block diagram of another embodiment of a converter for
television signals according to the present invention. Where, in
the drawings, the same numerals are applied to similar elements,
the detailed descriptions thereof are not repeated.
The difference between the first and second embodiments is that the
second embodiment further includes a switch 70, a color signal
generator 72 and a timing signal generator 74.
This second embodiment does not include display controller 66. A
controller 76 replaces controller 56 and includes more functions
than controller 56 described above with reference to FIG. 4. That
is, input terminals 701, 702 of switch 70 are connected to output
terminal 543 of switch 54 and color signal generator 72. Switch 80
is controlled by output signal S20 from timing signal generator
74.
Switch 70 selects and outputs S9 of switch 54 or an output signal
S21 of color signal generator 72 by timing signal S20 from timing
signal generator 74. Color signal generator 72 generates signal S21
corresponding to a predetermined color. Controller 76 changes the
connecting of switch 54 from terminal 541 to 542 if switch 64 is
operated while in the zoom mode. Simultaneously, controller 76
activates timing signal generator 74 and supplies information about
the selection position from switch 64. Timing signal generator 74
outputs timing signal S20 corresponding to the selection position.
The connection of switch 70 is changed to terminal 702 from 701
when timing signal S20 is generated from timing signal generator
74.
The operation of the second embodiment is described below with
reference to FIGS. 9 and 10.
FIGS. 9 and 10 illustrates pictures in a conventional TV system
according to the converter shown in FIG. 8 and a Hi-Vision system,
respectively.
Where the system is set to the zoom mode, signal S5 is selected by
switch 54. Signal S5 is supplied to output terminal 60 through
switch 70. Thus, portion 20 of Hi-Vision picture 22 (FIG. 1) is
fully displayed on the TV monitor (not shown).
If switch 64 is operated during the zoom mode, the connection of
switch 54 is changed from terminal 541 to terminal 542 to select
signal S11 from upper and lower panel adder circuit 52. According
to the selection position determined by switch 64, the phase of
timing signal S20 is changed. Thus, the picture is displayed
according to the selected position.
Timing signal generator 74 is activated by controller 76 and
information about the selection position is supplied to timing
signal generator 74 from controller 76. Timing signal generator 74
changes the phase of timing signal S20 according to the new
selection position.
Signal S11 from upper and lower panel adder circuit 52 is provided
to output terminal 60 through switches 54 and 70. The picture on
the display shows all of the Hi-Vision picture information in this
case. Additionally, the selection position is displayed on the
Hi-Vision picture. More particularly, as shown in FIG. 9, the
position is displayed by color frame 901. Picture 902 surrounded by
frame 901 corresponding to a portion 1001 of original Hi-Vision
picture 1002 (FIG. 10) where, S14 is a output from controller 76 to
right and left panel substraction circuit 46. Portion 903
corresponds with original Hi-Vision picture 1002.
Frame 901 is displayed by switching the output of switch 70 from
signal S9 to signal 521. Thus, if timing signal S20 is separated to
a horizontal and vertical direction, timing signal is shown as
S20H, (S20V in FIG. 9). Actually, horizontal and vertical timing
signals are supplied according to the TV monitor's scanning
frequency. Frame 901 is displayed in a color determined by color
signal generator 72. The phase of vertical timing signal S20V is
fixed while the phase of horizontal timing signal S20H is
controlled or determined by the selection position.
If the user stops the operation of switch 64, the connection of
switch 54 is changed to the last connection state, i.e., signal S5
in the zoom mode is output. The operation of timing signal
generator 74 is prevented by controller 76. Thus, timing signals
are not generated. The picture in the zoom mode is displayed
without display of frame 901.
According to the second embodiment of the present invention,
selection position is displayed when the selection position is
changed by the user. The user may thus confirm the changed
selection position visually. In this embodiment, the selection
position is displayed by using the transformation output in the
wide mode. Thus, in an apparatus including the wide transformation
mode, a new transformation circuit (converter) is not required.
The above embodiment displays the selection position only when the
selection position is changed by the user. However, a converter may
display the selection position on demand by the user. For example,
a selection position display switch 80 is further provided (FIG. 8)
and controller 76 controls timing signal generator 74 and switch 54
as well as when switch 64 is operated. Information with respect to
the selection position may be supplied from switch 164.
The converter may display a selection position which is
predetermined in the state that the wide mode is set yet. Also, in
this embodiment, signal is transformed from the Hi-Vision signal to
a conventional TV signal. However, the reverse process may also be
performed. That as shown in FIG. 11, portion 1101 of picture 1102
of a conventional TV system is converted in full to a Hi-Vision
system picture.
The present invention is not limited to converters which converts
Hi-Vision signal to the present TV signal. The invention also may
be applied to converters which convert one signal to another signal
where aspect ratios of both signals are different from each
other.
* * * * *